کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2436482 1107316 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A unique phosphatidylinositol 4-phosphate 5-kinase is activated by ADP-ribosylation factor in Plasmodium falciparum
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی انگل شناسی
پیش نمایش صفحه اول مقاله
A unique phosphatidylinositol 4-phosphate 5-kinase is activated by ADP-ribosylation factor in Plasmodium falciparum
چکیده انگلیسی

In eukaryotes, calcium signalling has been linked to hydrolysis of the phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). The final enzyme in the synthesis of this phosphoinositide, a Type I phosphatidylinositol 4-phosphate 5-kinase (PIP5K), is activated by the small G protein ADP-ribosylation factor 1 (ARF1). In mammals, the ARF-PIP5K pathway is a key regulator of cell motility, secretion and cell signalling. We report the characterisation of a unique, putative bifunctional PIP5K in the human malaria parasite Plasmodium falciparum. The protein comprises a C-terminal, functional PIP5K domain with catalytic specificity for phosphatidylinositol 4-phosphate. The recombinant enzyme is activated by ARF1 but not phosphatidic acid. The protein also incorporates an unusual N-terminal domain with potential helix-loop-helix EF-hand-like motifs that is a member of the neuronal calcium sensor family (NCS). Intriguingly, NCS-1 has been shown to stimulate phosphatidylinositol 4-phosphate synthesis by activating mammalian and yeast phosphatidylinositol 4-kinase β in vitro in a calcium-dependent manner. The unexpected physical attachment of an NCS-like domain to the plasmodial PIP5K might reflect a unique functional link between the calcium and PtdIns(4,5)P2 pathways allowing modulation of PtdIns(4,5)P2 production in response to changes in intracellular calcium concentrations within the parasite.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal for Parasitology - Volume 39, Issue 6, May 2009, Pages 645–653
نویسندگان
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